The present invention concerns a new process and the relative submerged plant, suitable for carrying out the submarine biopurification of the effluents (waste waters) discharged into the sea.
The field of the invention is that of the equipment used to purify, using marine organisms, the effluents (waste waters) discharged into the sea.
One of the most serious problems that arises in the operation of sewage disposal of small coastal towns, concerns the large difference in effluent volumes to be treated in the space of a year. In fact, during the summer season, peaks can be reached which are ten times greater than the winter averages. This prevents optimum functioning of the purification plants and has led to most civil services in coastal towns opting for the realization of pipes pouring out to sea. Also the lower costs and easier management suggested such a choice. However, pipes pouring out to sea have been realized, in most cases, without considering the hydrodynamic conditions of the receptor (the space of sea in front of) and often the sewage, untreated or only treated from a physical point of view (screening, sand trapping and sedimentation), arrives close to the shore due to the unfavourable interplay of currents, with well known unfortunate hygienic-health and aesthetic consequences. On the other hand, the costs to take the pipe and its diffuser down to an optimum depth (over 50-60 metres in depth) are prohibitive for the majority of Italian coastal towns.
The main aim of the present invention is to provide a process, and relative plant, suitable for allowing the disposal of effluent into the sea, which avoids drawbacks arising, connected with the discharge of sewage by means of traditional underwater pipes.
An additional aim of the invention is to provide a plant and a process that allow the aforesaid disposal, diluting and recycling the organic substances contained, in the sewage, cutting down the bacterial load so as to achieve the correct disposal of the effluent.
These and other aims of the invention are accomplished with the process and plant of the claims 1 and 7 respectively. Additional characteristics of the invention result from the remaining claims.
As regards known systems of sewage disposal into the sea, the process and plant according to the invention offer the advantage of overcoming both the hygienic-health drawbacks, as well as aesthetic ones unresolved until now. In addition, the process and plant according to the invention have the advantage of favouring the dilution in the sea and the recycling of organic substances contained in the sewage, carrying out the correct disposal of the effluent also through the desired cutting down the bacterial load contained in it.